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-rw-r--r--arch/s390/Kconfig1
-rw-r--r--arch/s390/include/asm/pgalloc.h3
-rw-r--r--arch/s390/include/asm/tlb.h22
-rw-r--r--arch/s390/mm/pgtable.c63
4 files changed, 61 insertions, 28 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 2b7c0fbe578..9015060919a 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -90,7 +90,6 @@ config S390
select HAVE_KERNEL_XZ
select HAVE_ARCH_MUTEX_CPU_RELAX
select HAVE_ARCH_JUMP_LABEL if !MARCH_G5
- select HAVE_RCU_TABLE_FREE if SMP
select ARCH_SAVE_PAGE_KEYS if HIBERNATION
select HAVE_MEMBLOCK
select HAVE_MEMBLOCK_NODE_MAP
diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h
index 8eef9b5b3cf..78e3041919d 100644
--- a/arch/s390/include/asm/pgalloc.h
+++ b/arch/s390/include/asm/pgalloc.h
@@ -22,10 +22,7 @@ void crst_table_free(struct mm_struct *, unsigned long *);
unsigned long *page_table_alloc(struct mm_struct *, unsigned long);
void page_table_free(struct mm_struct *, unsigned long *);
-#ifdef CONFIG_HAVE_RCU_TABLE_FREE
void page_table_free_rcu(struct mmu_gather *, unsigned long *);
-void __tlb_remove_table(void *_table);
-#endif
static inline void clear_table(unsigned long *s, unsigned long val, size_t n)
{
diff --git a/arch/s390/include/asm/tlb.h b/arch/s390/include/asm/tlb.h
index c687a2c8346..775a5eea8f9 100644
--- a/arch/s390/include/asm/tlb.h
+++ b/arch/s390/include/asm/tlb.h
@@ -30,14 +30,10 @@
struct mmu_gather {
struct mm_struct *mm;
-#ifdef CONFIG_HAVE_RCU_TABLE_FREE
struct mmu_table_batch *batch;
-#endif
unsigned int fullmm;
- unsigned int need_flush;
};
-#ifdef CONFIG_HAVE_RCU_TABLE_FREE
struct mmu_table_batch {
struct rcu_head rcu;
unsigned int nr;
@@ -49,7 +45,6 @@ struct mmu_table_batch {
extern void tlb_table_flush(struct mmu_gather *tlb);
extern void tlb_remove_table(struct mmu_gather *tlb, void *table);
-#endif
static inline void tlb_gather_mmu(struct mmu_gather *tlb,
struct mm_struct *mm,
@@ -57,29 +52,20 @@ static inline void tlb_gather_mmu(struct mmu_gather *tlb,
{
tlb->mm = mm;
tlb->fullmm = full_mm_flush;
- tlb->need_flush = 0;
-#ifdef CONFIG_HAVE_RCU_TABLE_FREE
tlb->batch = NULL;
-#endif
if (tlb->fullmm)
__tlb_flush_mm(mm);
}
static inline void tlb_flush_mmu(struct mmu_gather *tlb)
{
- if (!tlb->need_flush)
- return;
- tlb->need_flush = 0;
- __tlb_flush_mm(tlb->mm);
-#ifdef CONFIG_HAVE_RCU_TABLE_FREE
tlb_table_flush(tlb);
-#endif
}
static inline void tlb_finish_mmu(struct mmu_gather *tlb,
unsigned long start, unsigned long end)
{
- tlb_flush_mmu(tlb);
+ tlb_table_flush(tlb);
}
/*
@@ -105,10 +91,8 @@ static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
static inline void pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
unsigned long address)
{
-#ifdef CONFIG_HAVE_RCU_TABLE_FREE
if (!tlb->fullmm)
return page_table_free_rcu(tlb, (unsigned long *) pte);
-#endif
page_table_free(tlb->mm, (unsigned long *) pte);
}
@@ -125,10 +109,8 @@ static inline void pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
#ifdef __s390x__
if (tlb->mm->context.asce_limit <= (1UL << 31))
return;
-#ifdef CONFIG_HAVE_RCU_TABLE_FREE
if (!tlb->fullmm)
return tlb_remove_table(tlb, pmd);
-#endif
crst_table_free(tlb->mm, (unsigned long *) pmd);
#endif
}
@@ -146,10 +128,8 @@ static inline void pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
#ifdef __s390x__
if (tlb->mm->context.asce_limit <= (1UL << 42))
return;
-#ifdef CONFIG_HAVE_RCU_TABLE_FREE
if (!tlb->fullmm)
return tlb_remove_table(tlb, pud);
-#endif
crst_table_free(tlb->mm, (unsigned long *) pud);
#endif
}
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 373adf69b01..6e765bf0067 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -678,8 +678,6 @@ void page_table_free(struct mm_struct *mm, unsigned long *table)
}
}
-#ifdef CONFIG_HAVE_RCU_TABLE_FREE
-
static void __page_table_free_rcu(void *table, unsigned bit)
{
struct page *page;
@@ -733,7 +731,66 @@ void __tlb_remove_table(void *_table)
free_pages((unsigned long) table, ALLOC_ORDER);
}
-#endif
+static void tlb_remove_table_smp_sync(void *arg)
+{
+ /* Simply deliver the interrupt */
+}
+
+static void tlb_remove_table_one(void *table)
+{
+ /*
+ * This isn't an RCU grace period and hence the page-tables cannot be
+ * assumed to be actually RCU-freed.
+ *
+ * It is however sufficient for software page-table walkers that rely
+ * on IRQ disabling. See the comment near struct mmu_table_batch.
+ */
+ smp_call_function(tlb_remove_table_smp_sync, NULL, 1);
+ __tlb_remove_table(table);
+}
+
+static void tlb_remove_table_rcu(struct rcu_head *head)
+{
+ struct mmu_table_batch *batch;
+ int i;
+
+ batch = container_of(head, struct mmu_table_batch, rcu);
+
+ for (i = 0; i < batch->nr; i++)
+ __tlb_remove_table(batch->tables[i]);
+
+ free_page((unsigned long)batch);
+}
+
+void tlb_table_flush(struct mmu_gather *tlb)
+{
+ struct mmu_table_batch **batch = &tlb->batch;
+
+ if (*batch) {
+ __tlb_flush_mm(tlb->mm);
+ call_rcu_sched(&(*batch)->rcu, tlb_remove_table_rcu);
+ *batch = NULL;
+ }
+}
+
+void tlb_remove_table(struct mmu_gather *tlb, void *table)
+{
+ struct mmu_table_batch **batch = &tlb->batch;
+
+ if (*batch == NULL) {
+ *batch = (struct mmu_table_batch *)
+ __get_free_page(GFP_NOWAIT | __GFP_NOWARN);
+ if (*batch == NULL) {
+ __tlb_flush_mm(tlb->mm);
+ tlb_remove_table_one(table);
+ return;
+ }
+ (*batch)->nr = 0;
+ }
+ (*batch)->tables[(*batch)->nr++] = table;
+ if ((*batch)->nr == MAX_TABLE_BATCH)
+ tlb_table_flush(tlb);
+}
/*
* switch on pgstes for its userspace process (for kvm)